Chicken gravy from stock cubes??

[CSMonkeh]

This is kinda urgent (and also a n00b in this particular sub-forum) but getting off-the-shelf GF gravy is proving hard tonight and we were planning chicken pies for dinner
Do have some OXO Succulent Chicken stock pots - is it as simple as adding cornflour to it to thicken it?
Usually use sachets to make up 300ml so thats what quantity we're after

Thanks guys

 

[CSMonkeh]

It supposedly has garlic and thyme in it.
Can't have onions - make me sick

So just gently heat say 250ml water with stock cube and add cornflour??